1. Field of the Invention
The present invention generally pertains to a connector structure incorporating a cable reel and combined switch systems, suitably used in automobiles and other motor vehicles. Such a connector structure is mounted on or around a steering shaft of a vehicle. The general purpose of the present invention is to provide a connector device for the steering shaft, which is configured such that it can be mounted simply by assembling unit modules.
2. Description of Background Information
A known steering shaft includes a main shaft body, around which is provided a connector structure including a cable reel, combination switches, a cancel cam, a main scale, an encoder, and the like. As shown in FIGS. 1 and 2, a mobile body portion 5 of the cable reel 1 is fixed to the bottom end of a steering wheel via means forming a lobe (not shown in the figures). A fixed body portion 2 of the cable reel 1, to which the mobile body portion 5 is fitted in a freely rotatable manner, is then fitted on a combination switch body 3, the latter being in turn fixed to a steering column 4. One side of the combination switch body 3 is provided with a turn-indicator unit (winker or blinker unit) 7, which includes a housing 7a storing circuit elements 7b such as a turn signal-indicator switch (winker or blinker switch), and a turn signal lever 7c. The other side of the combination switch body 3 is provided with a lighting unit 8, which includes a housing 8a storing circuit elements 8b such as a lighting switch, and a lighting lever 8c. 
A space is formed between the combination switch body 3 and a steering shaft 9, located beneath the cable reel 1. Inside this space, the cancel cam 10 is fixed to the steering shaft 9, while the encoder (steering angle sensor) 11 is fixed to the steering column 4.
The cable reel 1 is in the form of a hollow torus defined by the fixed body portion 2 and the mobile body portion 5. The cable reel 1 can thus contain a flat cable 6 stored in a spiral. One end of the flat cable 6 is fixed to the fixed body portion 2, while the other end is fixed to the mobile body portion 5, so that the signals passing through the flat cable can be transmitted to outside. When the steering wheel is turned, the mobile body portion 5 is rotated clockwise or counter-clockwise correspondingly, and the flat cable 6 is likewise wound or unwound in the cable reel.
According to the above conception known in the prior art, the connector devices constituting a connector structure are mounted one by one around the steering shaft along the vehicle""s production line. As a result, these devices are prone to be mounted askew relative to their intended positions with respect to the main axis of the steering shaft. Likewise, because the connector devices such as a turn indicator unit 7, a lighting unit 8, a cable reel 1, a cancel cam 10 and an encoder 11, are mounted individually, they must be prepared as individual units prior to assembling. Each connector device thus requires an individual housing and fixing means (e.g. bolts) or the like. The number of required spare parts is thus augmented.
In the above-mentioned prior art, each connector device is stored in an independent housing, and the cable reel 1 is mounted into the combination switch body 3. Because of this construction, the dimensions of the connector structure are made greater and larger as a whole. As a result, its weight is also increased. Moreover, the connector devices are usually manufactured by different manufacturers. Accordingly, when the connector device are being assembled, a certain degree of clearance must be provided between them, and an otherwise unnecessary space must be envisaged. The connector structure is thus made even larger.
In view of these problems, it is an object of the present invention to provide a connector structure in unitary modules, so that they can be mounted together on a production line and installed without misfitting with respect to their intended positions relative to the steering shaft axis. Another object is to reduce the number of necessary construction parts and assembly steps. Yet another object is to prevent the connector structure from scaling up and increasing weight by altering the relative position where the cable reel is mounted.
To this end, there is provided a connector structure incorporating a cable reel and switch system, the connector structure including a connector shell having an axis, and configured to be joined with a steering shaft having an axis, so that both axes can be joined.
The connector shell includes a cylindrical section, with two end portions, fitting around the steering shaft in a freely rotatable manner. The connector shell further includes a receptacle section including a shoulder portion enlarging from one end portion of the cylindrical section, a peripheral sidewall portion, and first and second parting strip portions symmetrically provided with respect to the axis of the connector shell, thereby forming, inside the receptacle section, a central zone between the first and second parting strip portions, a first peripheral zone between the peripheral sidewall portion of the receptacle section and the first parting strip portion, and a second peripheral zone between the peripheral sidewall portion of the receptacle section and the second parting strip portion.
The cable reel is then fitted and fixed in the central zone of the receptacle section.
The switch system includes at least a turn-indicator system and a lighting system, respectively fitted and fixed in the first peripheral zone of the receptacle portion and the second peripheral zone thereof.
Preferably, the cable reel includes a mobile body portion including a top wall and an internal sidewall, and the top wall includes a cancel cam formed unitarily and in one piece therewith.
Preferably yet, the cable reel includes a mobile body portion including a top wall and an internal sidewall with projecting portions, the projecting portions being fixed with a main scale, and the cable reel further includes a fixed body portion including a bottom wall and an external sidewall. The latter defines a third peripheral zone together with the peripheral sidewall portion of the receptacle section in a zone biased from said first and second peripheral zones around the axis of the connector shell, and the third peripheral zone contains an encoder, such that the encoder can detect the steering angle of the main scale.
Suitably, the connector structure further includes a shell lid which includes a top wall with a center hole and an external sidewall. The center hole is adapted to be passed through with the main axis of a steering wheel in a freely rotatable manner, and the top wall and the external sidewall cover the connector shell.
Preferably, the shell lid can also serve as a steering column cover.
As understood from the above, the connector shell is constructed substantially concentrically with respect to the main axis of the steering shaft. As the cable reel, turn-indicator system and lighting system are contained in such a connector shell, they are prevented from being biased from the predetermined positions when they are mounted around the main axis of the steering shaft. Further, the bottom end of the cylindrical section includes a flange portion which fixes to the steering column, so that the mounting site is limited to only one position. Accordingly, the mounting steps in the assembly line for automobiles can be reduced.
As the turn-indicator and lighting systems are stored in the connector shell, they are not required to be protected in separate housings. Further, the functional parts for these systems are stored as a whole in the connector shell. This can thus obviate the need for a space normally required for the separate housings. In addition, the cable reel is inserted into the central zone between the first and second parting strip portions. Accordingly, the height and horizontal size of the integrated connector structure can be reduced, and the entire structure becomes more compact. Furthermore, combination switches such as a turn-indicator system or a lighting system are not required to be protected in separate housings. Functional parts can thus be easily modified in or added to the above systems.
In the prior art connector structure, the connector devices, to be incorporated into the connector structure, are often supplied by different manufacturers. In such a case, a certain degree of clearance between different connector devices must be provided. In the inventive connector structure, such a clearance is no longer required, so that the corresponding space, otherwise necessary, can be eliminated. As a result, the connector structure can further be miniaturized.
The top area of the mobile body portion of the cable reel, which is contained in the connector shell, is provided with a cancel cam, while the bottom area thereof is provided with a main scale. Further, an encoder is provided in the peripheral zone formed between the cable reel and the peripheral sidewall portion of the connector shell. The position of the main scale can then be detected by the encoder. Typically, the peripheral zone where the encoder is installed is arranged in a position perpendicular to the axis linking the peripheral zones where the turn-indicator system and the lighting systems are located respectively.